1. Field of the Invention
The present invention relates to an individuals checking apparatus, or a human body checking apparatus, for checking fingerprints or like characteristics of individuals for identification purposes.
2. Background Art
There are cases where it is desired to restrict unauthorized entry into a certain area of a building. Measures to enforce such restriction may typically involve setting up a special door in the passage or entrance to the restricted area. The door may be electrically locked and unlocked by use of a fingerprint checking device installed nearby so that only authorized personnel may gain access to the area.
In operation, a fingerprint sensor of the fingerprint checking device captures an image of the fingerprint(s) of a person""s specific finger(s) and converts gradations of the captured image to electrical signals from which to generate fingerprint data. The data thus obtained are checked against previously stored fingerprint data to see if there is a match between the two kinds of data.
Typically, a numeric keypad is attached outside the fingerprint sensor. When an operator operates the keypad to enter his or her identification (personal) number, the fingerprint data corresponding to the ID number are retrieved from the previously recorded fingerprint characteristic data.
The retrieved data are checked against the actually detected fingerprint data having been entered the fingerprint sensor.
In the above setup, the probability of false acceptance (i.e., someone else mistaken for an authorized person) through inadequate fingerprint verification may be reduced by checking a plurality of fingers of each person using an AND condition. Specifically, fingerprint data about a plurality of fingers of each authorized person are stored in advance. Only when the fingerprint data on all the fingers are matched, the person being checked is authorized for entry. Such a system is proposed illustratively in Japanese Patent Laid-open No. Sho 61-177580.
It may happen that the operator has his or her finger(s) injured and rendered useless for fingerprint checkup, or that fingerprints from a particular finger(s) cannot be recognized for some reason for identification. Such contingencies are addressed illustratively by checking a plurality of fingers of each person using an OR condition so as to reduce the probability of false rejection (i.e., an authorized person falsely rejected) through inadequate fingerprint verification. Specifically, fingerprint data about a plurality of fingers of each authorized person are stored in advance. If any one of the checked fingers matches the previously recorded fingerprint data, the person being checked is authorized for entry. This system is proposed illustratively in Japanese Patent Laid-open No. Hei 7-120417.
As outlined, the conventional fingerprint checking devices typically involve storing fingerprint data about a plurality of fingers of each authorized person in advance, and checking a plurality of fingers of each person using an AND or OR condition for enhanced checking performance. The AND and OR features, intended to reduce the probability of false acceptance or rejection, requires installing an AND function and an OR function separately in discrete components constituting the checking device.
Further, people""s fingers have diverse characteristics: fingerprints may be prominent or inconspicuous, some fingertips may be constantly damp, and some fingers may have scars from injuries. Given such diversity, people often have difficulty in getting identified correctly under predetermined checking conditions. Furthermore, identity recognition performance can be worsened by the adoption of the AND or OR check.
In addition, there is a trade-off between the probability of false acceptance and that of false rejection, two basic parameters that determine fingerprint checking performance. That is, one probability is improved at the expense of the other with regard to a certain set of verifying conditions.
It is therefore an object of the present invention to overcome the above and other deficiencies and disadvantages of the prior art and to provide an easy-to-use human body checking apparatus for allowing either AND or OR checking to be selected on an personal basis so that identity checking performance is optimized to accommodate differences of human body characteristics of individuals.
According to one aspect of the present invention, an individuals checking system checks captured data of individuals characteristic point against previously recorded data of individuals characteristic point to see if there is a match therebetween. The system comprises an apparatus for recording of individuals characteristic point data and an apparatus for checking individuals characteristic point data. The apparatus for recording records a plurality of individuals characteristic point data on a plurality of persons to a database and for sets a checking mode and a checking level for the individuals characteristic point data for each of the persons. The apparatus for checking checks a captured individuals characteristic point data on a given person against the recorded individuals characteristic point data in the checking mode and at the checking level set for each of the persons.
In the system, the checking mode may include an AND checking mode and an OR checking mode. The AND checking mode may be a mode in which all of the captured individuals characteristic point data are checked against the recorded individuals characteristic point data for a match. The OR checking mode may be a mode in which one of the captured individuals characteristic point data is checked against the recorded individuals characteristic point data for a match.
In the system, the apparatus for recording the individuals characteristic point data may include an recording means of individuals characteristic point data, monitoring means of recording status, and determining means of checking mode/level.
The recording means of individuals characteristic point data may continuously record a plurality of individuals characteristic point data about each person wishing to register with the apparatus. The monitoring means of recording status may monitor difficulties in characteristic point data recognition depending on a state of individuals characteristic points of a given person. The determining means of checking mode/level may determine the checking mode and checking level suitable for each person in accordance with the recording status of individuals characteristic points.
In the system, the apparatus for checking the individuals characteristic point data may include checking mode retrieving means and checking level retrieving means. The checking mode retrieving means may retrieve a checking mode corresponding to an input ID number from among the individuals characteristic point data recorded in the database. The checking level retrieving means may retrieve a checking level corresponding to the input ID number from among the individuals characteristic point data recorded in the database.
In another aspect, the system may further comprise a checking and judging apparatus of multiple individuals characteristic point data. The checking and judging apparatus may check captured individuals characteristic point data against the individuals characteristic point data recorded in the database in accordance with the retrieved checking mode and checking level, and may judge the results of the checking.